Telephone ringing system



June 21, 1932. .1. w. GOODERHAM 1,364,051

TELEPHONE RINGING SYSTEM Filed Sept. 12, 1931 4 Sheets-Sheet 1 TO OTHERTESTING APPARA TUS 'lNl/ENTOR J. W. GOODERHAM ATTORNEY June 21, 1932. Jw GOODERHAM 1,864,061

TELEPHONE RINGING SYSTEM Filed Sept. 12, 1931 4 Sheets-Sheet 2 To OTHERTESTING APPARA 703 TO OPER.

p SET AT'i'ORA/Ey 1 1932- J. w. GOODERHAM 1 TELEPHONE RINGING SYSTEMFiled Sept. 12, 1931 4 SheetsSheet 4 SUB FIG. 4.

POLARIZED POLARIZED INVEN TOR J. W. GOODERHAM A TTORNEV Patented June21, 1932 WED] v s'm ss JOHN w. GoonsnHAM, or LARCHM'ONT, NEW YORK,ASSIGN-OB, T BELL TELEPHONE 253 the application of ringing current to atrunk LABORATGRIES, INCQRPGBATED, 0.13 NEW YORK, N. Y.,

YORK

A CORPORATION OF NEW TELEPHONE iR-INGING SYSTEM Applicationfiledseptemberim, 1931. Serial No. 562,446.

i centralization of the information and toll oilices has arisen thecentralization of the work of the test man. Some of the tests of asubscribers line are pertormed with the receiver on the switchhook whileothers require removal of the receiver. It is, therefore, necessary thatthe control of the application of the ringing current remain with thetest man. Where a. considerable distance separates the oiiice at whichthe test desk is locatedfrom the office serving the subscribers line theringing current as received at that oiiice may not have sufiicientstrength to opcrate the ringer properly.

In accordance with the present invention,

outgoing from an operators deskcauses the association ofthe trunk at thedistant ofiice with means for testing-for the nature of the appliedringing current and the response of the testing means causes theapplication ofthe same type of ringing current to the outgoing end ofthe trunk and thence to the subscribers line. The removal of thereceiver causes the disconnection of the ringing current from both endsof the trunk line.

The invention has been disclosed in connection with a skeletonizedshowing of a test circuit similar to that shown and described in detailin Patent 1,632,902 to L. H. Johnson, June 21,1927. The drawings includethe following figures:

Fi l which shows a set of manual ringing keys and a transfer key;

Pig. 2 which shows a set of machine ringing keys;

Fig. 3 which shows the end of a trunk C11- cuitat the test desk; and

Fig. l which shows the terminating plug of the trunk, and a subscriberlsline at the right of the dotted line, and the remote control ringingequipment at the left of that line. 1

The test circuit includes a primary test cord and a secondary test cord.Associated with each test cord are a number of testing arrai-i-geinentsby whiehtests may be made on a .subscribers line and the equipmentassociated therewith. The tests normally made with the primary cordrequire the constant attention of the test man and are performed more orlessrapidly. The testsnormally performed. with the secondary test cordrequire a longer time and may require the attention of thetest man onlyintermittently, after the connection has been established. For adescription of this test equipment, reference may be made totheaboveidentified J ohnsou mary and secondary test cords may be re versed},that is, connected to the equipment normally associated with the othercord. By the use 0t this key, therefore, it is possible to signal asubscriber with either type of 'ingin-g current and then to make suchtests as are necessary.

The manual ringing keys would ordinarily.

be used in signaling a subscriber located in a nearby ofiice, or forsignaling operating desksin a more distant office, since they have noefiect on the remote control'equipmentof Fig. 4, as will be shownhereinafter. For signaling subscribers associated'with distant offices,the-machine ringing would ordinarily be used so that, it may be relayedto the subscribers substation by the remote control equipment.Insignaling nearby ofiices, the remote control equipment would not benecessary andtrnnks appearing, at those offices wouldinclude theequipment of Fig. 3 connecteddirectly to the incoming plug and assowhichin turn operates relay 307. Relay 307 closes a circuit for lamps such aslamp 309 at each position at which the trunk appears, to

, mark the trunk busy. The identity of the substation is passed by meansof a call wire or talking trunk (not shown) to the operator at whoseposition the trunk appears in plug 402. Plug 402 is then inserted intojack 401. A circuit is then closed from ground through the winding ofcut-oft relay437sleevesofjack 401and plug 402, normal contact of relay422, resistance 421, winding of relay 420 to battery. l/Vith relay 420operated, a circuit is closed from ground through the windings of relays432 and 435, front contact of relay 420, conductor 442 to conductor 315,winding of relay 313, inner lower back contact of relay 305, lower frontcontact of relay 303, sleeves of jack 300, plug 301, and cord 100, outerlower normal contact of key 107 winding of relay 115 to battery. Relay115 operates, lighting lamp 118 as an indication that the line has beenconnected with the test circuit. Relay 432 operates, closing an obviouscircuit for relay 433 which in turn operates relay 434. Relay 434 locksunder the control of relay 420. Relay 435 does not operate in thiscircuit, being marginal. Relay 313 also operates in this circuit,closing. a circuit for relay 308 which closes a locking circuit foritself from battery through its lower winding and inner lower contact,inner upper back contact of relay 305, inner upper front contact ofrelay 307 to ground at the outer upper front contact of relay 308. Relay307 is also held operated in this circuit.

After such tests have been made as are made with the receiver on theswitchhook, if the test man wishes the receiver removed, he will operateone of the ringing keys 101 to 104 if the substation is one on afour-party line, one of keys 105 and 106 if the substation is one on atwo-party line, or key 106 if it is an individual line. Assuming thatkey 101 is the proper key to use for this substation, the operation ofthe key closes a circuit from ringing source 109, ballast lamp 108,upper operated contact of key 101, upper normal contacts of keys 102 to107, tips of cord 100, plug 301 and jack 300, outer upper back contactof relay 305, conductors 316 and 440, tips of plug 402 and jack 401,through the ringer at substation 400, back over the rings of jack 401and plug 402, conductors 441, and

a 317, outer lower back contact of relay 305,

rings of jack 300, plug 301 and cord 100,

lower normal contacts of keys 107 106, 105,-

104, 103 and 102, lower operated contact of key 101, key 114 to ground.When the receiver is removed from the switchhook at substation 400 andthe ringing key is normal, a direct current circuit is closed throughthe substation and extending over the inner upper normal contact of key101 to the upper left winding of repeating coil 120 and ground, and overthe lower normal contact of key 101, winding of relay 121, lower leftwinding of repeating coil 120 to battery. Relay 120 when it operates inthis circuit connects ground through resistance 122, in shunt of lamp118, extinguishing that lamp as an inclication to the test man that thereceiver has been removed.

If the test man wishes to hold the line while he makes other tests withthe test cord, he may remove the plug 301 from ack 300 without releasingthe attached line. The removal of the plug releases relay 303 whichconnects battery through resistance 304 over its inner lower backcontact, and the inner lower back contact of relay 305 to the winding ofrelay 313 holding relays 313 and 432 operated. Relays 308 and 307 alsoremain locked as above described. With relay 303 released and relay 307operated, battery through the winding of relay 312 is connected over theouter lower front contact of relay 307, outer lower back contact ofrelay 303, to the ring side of the trunk and ground is connected overthe outer upper front contact of relay 307 and the inner upper backcontact of relay 303 to the tip side of the trunk. If the receiver isremoved from the switchhook under these conditions, or the ring side ofthe line is grounded, or a field test man connects his telephone acrossthe line, relay 312 operates closing an alarm circuit. It also completesa circuit from battery through interrupter 314, outer lower frontcontact of relay 308, upper front contact of relay 312, to lamp 311 ateach position at which the trunk appears to attractthe attention of anoperator or test man.

In order to release the trunk it is necessary for the test man tooperate key 310 with plug 301 removed from the jack 300. As abovedescribed, the removal of the plug releases relay 303, while relays 313,307 and 308 remain operated. The closure of key 310 connects ground overthe contact of the key, hack contact of relay 303 to the winding ofrelay 305 and battery. Relay 305 disconnects the tip and ring conductorsof the trunk from the jack, connects battery through low resistance 306in series with the windings of relays 313, 435 and 432 and opens backcontact of relay 405.

tact of relay 303, inner upper front contactof relay 308, upper frontcontact of relay 30o, innerupper front contact of relay 307, to groundat the outer upper front contact of relay 308. This prevents the releaseof relay 305 until the connection has been released at the distant end.Relay 435 operates in series with the low resistance 306 and lights lamp436. In response to the lighting of lamp 436, plug 402 is withdrawn fromjack 401, releasing relay 420 and opening the circuit of relays 432, 435and 313 which release. Relay 432 in turn releases relays 433 and 434.The release of relay 313 opens the energizing circuit of relay 308 andthat relay releases in turn releasing relays 307 and 305. With relay 307released, lamp 309 is extinguished to indicate that the trunk has beenrestored to normal.

If the manual ringing keys are used for signaling over a trunk whichincludes remote control ringing equipment, the circuits will include allof the equipment shown in Fig. 4, and conductor 315 will be connected toconductor 442 through the winding of polarized relay 406, conductor 316will be'connected to conductor 440 over the upper back contact of relay405 andconductor 317 will be connected to conductor 441 over the lowerSince relay 406 is polarized, so as to be unresponsive to the current inthe sleeve circuit over cord 100, ringing takes'place exactly as abovedescribed.

If machine ringing is to be used on a direct trunk, that is, one withoutthe remote control ringing equipment, plug 302 is inserted in jack 300.Relays 303 and 307 are operated as previously described. The sleevecircuit, which is completed when plug 402 is inserted in jack 401 of'theline under test, may be traced as before through the windings of relays432,435 and 313 to the sleeves of jack 300, plug-302 and cord 150,

k outer upper left normal contacts of key 107,

winding of relay 116, inner upper back contact of relay 210, resistance212 to battery. Relays 432 and 313 function as previously described,relay 435 being unope-rated. Relay 116 operates relay 117 which in turnlights lamps 119 as an indication that the line has been connected tothe test circuit. Keys 214,215, 216 and 217 correspond in the type ofringing applied to keys 103, 104, 101 and 102 respectively. Tosignalsubscriber 400 then, key 216 will be operated. The operation ofkey 216 closes a circuit from ground at its outer upper operated contactover the lower normal contacts of keys 215 and 213, through the windingof relay 219 to battery. Relay 219 transfers the ringing circuit fromnegative source 221 to positive source 223. Key 216 also closes acircuit from ground over the outer upper contact of key 216, over thelower normal contact of key 217, lower normal contacts of relay 206,winding of. relay 210 to battery. Relay 210 in operating disconnectsnegative battery through resistance 212 from the sleeve circuit andconnects positive battery through resistance 211 thereto, but since theremote control ringing circuit is not included in the outgoing trunkthis operation. is ineffective. It also connects ground over its upperfront contact, front contact of relay 117, through the winding of relay206, and resistance 208 to battery. However, a cire cult is also closedover the back contacts of relays 204, 205 and 206, to resistance 208 inshunt of the winding relay 206 preventing its operation at this time.Another branch of this circuit extends over the inner upper back contactof relay 206 to the winding of relay 201 and battery. Relay 201disconnects the talking conductors from the repeat.-

ing coil 224 and connects them to the ring-.

ing keys, preparing the ringing circuit. Re lay 210 also extends itsoperating circuit to the winding of relay 218 which also operates but isineffective. Relay 210 completes the ringing circuit which may be tracedfrom positive superimposed source 223 through ringing interrupter 222,front contacts of relay 219, outer lower front contact of relay 210,winding of relay 205, upper normal contact of key 213, inner upperoperated contact of key 216, upper normal contact of key 217, uppernormal contact of relay 201, upper right contact of key 107, tips ofcord 150,

plug 302 and jack 300, over the upper back contact of relay 305,conductors 316 and 440, tips of plug 402 and jack 401, through theringer at substation 400,rings of jack 401 and plug 402, conductors 441and 317, outer lower backcontact of relay 305, rings of jack 300, plug302 and cord 150, lower right contact of key 107, lower front contact ofrelay 201, outer lower normal contact of key 217, lower operated contactof key .216, ground. Relay 205 does not operate in this circuit, butwhen the receiver is removed at the substation 400, the circuit isaltered so that relay 205 doesoperate. The operation of relay 205 opensthe shunt around the winding of relay 206 which now operates,

opening the shunt at its own contact so that the release of relay 205cannot reclose it and looks over its lower alternate contact, innerlower normal contact of key '217 to ground at the outer upper operatedcontact of key 216. It also opens the circuit of relay 210 whichreleases in turn releasing relay 218, opening the ringing circuit,withdraw- I ing the connection of negative batteryfrom the sleevecircuit and reconnecting ground to the operators telephone set to permitthe connection of the telephone with the trunk. Relay 206 lights lamp209 as a signal that the. call has been answered and opens the circuitof relay 201 to connect the line through to the testing apparatus. Thetest man can now release the ringing key in turn releasing relay 206,extinguishing lamp 209. The release of relay 201 also extends the lineto the repeating coil 224 and relay 225. Relay 225 in operating connectsground through resistance 226 in shunt of lamp 119 extinguishing thatlamp as a signal that the receiver is off the switchhook at the lineunder test.

Assuming now that the line 400' to be tested lies in a distant office,and that the secondary cord 150 has been inserted in a trunk includingthe remote control ringing equipment of Fig. 4, the action of themachine current. Relay 405 also prepares a circuit for relay 409 frombattery through resistance 407, inner lower contact of relay 405,Winding of relay 409 to ground, but ground isconnected over the backcontact of relay 408 and the back contact of relay 409 in shunt of thewinding of relay 409 to prevent its operation at this time. Relay 405also connects ground to conductor 443. The ringing circuit is firstextended to means for identifying the side of the line to which ringingcurrent has been applied. Assuming that key 216 has been operated asbefore described, the ringing circuit extends from source 223 aspreviously traced to conductor 316, outer upper front contact of relay405, upper back contact of relay 404, lower back contact of relay 403,condenser 439, winding of relay 418 to ground and from ground over thelower operated contact of key 217 to conductor 317 as above described,outer lower front contact of relay 405, lower back contact of relay 404,upper back contact of relay 403, condenser 411, winding of relay 410 toground. Relay 418 responds to ringing current applied to the tipconductor, but relay 410 cannot operate in series with ground. Relay 418in operating extends the ringing circuit over its front contact, to theupper winding of relay 414, resistance 415 and ground. Relays 410 and418 and 414 together present a combination which will not operatefalsely on currents due to capacitiesin the trunk, etc. Relay 414 inoperating looks from battery through its lower winding to groundedconductor 443. It also closes a circuit from battery through the windingof relay 403, upper contact of relay 414, outer lower contact of relay409 to grounded conductor 443.

Relay 403 in operating transfers the ringing circuit from relays 418 and410 to polarized relays 417 and 429 which test for the polarity of thesuperimposed ringing current. The circuit extends from the upper frontcontact of relay 405 over the upper back contact of relay 404, innerlower front contact of relay 403, through the impedance networkincluding retard coil 430, condenser 431 and resistance 419, windings ofrelays 429 and 417, inner upper front contact of relay 403, lower backcontact of relay 404, to the outer lower front contact of relay 405.Since it was assumed that positive superposed ringing current was used,relay 429 will operate, in turn operating relay 428 which looks togrounded conductor 443. With relay 428 operated the outgoing ringingcircuit is established from positive superimposed ringing source 427,ringing interrupter 426, front contact of relay 428, back contact ofrelay 416, winding of relay 408, outer lower front contact of relay 403over the tip conductor 440, tips of plug 402 and jack 401, through thesubstation ringer to the rings of jack 401 and plug 402, ring conductor441, outer upper front contact of relay 403 to ground. The subscriberis, therefore, signaled with the proper kind of ringing current appliedto the proper side of the line.

Relay 408 cannot operate in series with the substation ringer, but whenthe receiver is removed, it does'operate. The operation of relay 408removes the shunt from the winding of relay 409 which now operates,further opening the shunt around its winding. It also opens the circuitof relay 403 to disconnect the outgoing ringing current from the line.In addition it connects the outer upper and outer lower front contactsof relay 405 together at it upper contact, completing a circuit forrelay 205 in which that relay can operate. The effect of the operationof relay 205 is the same as previously described. The release of relay210 restores the connection of negative battery to the sleeve circuitcausing the release of relay 406 which in turn releases relays 405, 414and 428 restoring the remote control ringing circuit to normal. Theremaining functions of the equipment are the same as previouslydescribed. Relays 412-, 416 and 404 perform the same functions forringing current connected to the ring side of the line as relays 414,428 and 403 performed when the ringing current was connected to the tipside of the line.

Key 213, in combination with keys 214 to 217, provides a low voltageringing current for the adjustment of ringers without excessive noise.The operation of key 213 connects continuous ringing current source 225over the outer lower operated contact of key 213 to ground. Assumingthat the ringer of substation 400 is to be adjusted, key 216 will alsobe operated and a circuit is closed from ground over the outer upperoperated contact of key 216, lower normal contact of key 215, innerlower operated contact of key 213, winding of relay 202, resistance 203to battery. Relays 210 and 218 are also Operated over key 216 aspreviously described. The ringing circuit extends from source 229through potentiometer coil 228 to its middle tap, front contact of relay218, outer upper operated contact of key 213, inner upper and outerlower front contacts of relay 202, winding of relay 204, through battery22.7 which supplies the superimposed positive potential, outer upper andinner lower front contacts o-frelay 202, inner upper operated contactsof keys 213 and 216, upper normal contact of key 217, upper frontcontact of relay 201 over the ringing circuit as previously traced backto the lower front contact of relay 201, outer'lower normal contact ofkey 217, lower operated contact of key 216 to ground. The location ofthe tap on the potentiometer 228 is so arranged that approximately siXtyvolts of the continuous ringing current is used. This arrangement would,of course, be used only where the substation can be rung directly.

From the foregoing description and a consideration of the drawings, itwill be clear 110w the circuits function when ringing over the tipconductor or when using negative superimposed ringing current.

What is claimed is:

1. In a telephone system, a first oflice, a plurality of sources ofringing current at said first oiiice, a second office, asimilarplurality of sources of ringing current at said. second ofiice, atrunk circuit connecting said offices, a telephone circuit outgoing fromsaid second office, means to apply ringing current from one of saidsources at said first oiiice to said trunk circuit, means associatedwith said trunk circuit at said second office fordetermining the natureof incoming ringing cur rent, and means responsiveto the operation ofsaid determining means to apply ringing current from the correspondingone of said plurality of sources at said second office to said outgoingtelephone circuit.

2. In a telephone system, a plurality of sources of ringing currentdiffering in polarity at a first office, a similar plurality of sourcesof ringing current at a second ofiice, V

a trunk circuit connecting said oflices, a telephone circuit outgoingfrom said second office, means to apply ringing current from either oneof said sources of ringing current at said first office to either sideof said trunk circuit, means associated with said trunk circuit at saidsecond ofiice for testing the conductors of said trunk for said ringingcurrent, means thereupon effective for testing the polarity of theincoming ringing current, and means responsive to the operation of saidtesting means to cause the application of ringing current of the samepolarity to the i same side of said outgoing telephone circuit.

3. In a telephone system, a plurality of sources of ringing currentdiifering in polarity at a first office, a similar plurality of sourcesof ringing current at a second office,

atrunk circuit connecting said ofiices, a telephone circuit outgoingfrom said second office, means to apply ringing current from either oneof said sources of ringing current at said first oflice to either sideof said trunk circuit, a pair of alternating current relays at saidsecond ofiicc, means to associate said relays with the two sides of saidtrunk to test for the presence of ringing current, a

pair of polarized relays, means responsive- 4. In a telephone system, fafirst office, a

plurality of sources of ringing current at said first ofiice, a secondofiice, a trunk circuit connecting said offices, means to prepare atalking circuit over said trunk circuit, means at said first office toapply ringing current from one: of said sources to said trunk circuit,means at said second oiiice for testing the nature of the incomingringing current, and means responsive to the operation of said applyingmeans to open said talking circuit at said second office and toassociate said testing means with said trunk.

, 5. In a telephone system, a first plurality ofsources of ringingcurrent, a correspondingsecond plurality of sources of ringing current,a trunk circuit, means to apply ringing current from one of said firstplurality of sources to the incoming end of said trunk circuit, testing,means for determining the nature of the ringing current applied, meansreponsive to the operation of said applying means to associate saidtesting means with said trunk circuit, and means responsive to 'saidtesting means to apply ringing current from the corresponding secondsource tothe outgoing end of said trunk circuit;

'6. In. a telephone system, a first office, a plurality of sources ofringing current at said-first oflice, a second oifice, a trunk circuitconnecting said oflices, means'for preparing a talking circuit over saidtrunk circuit, means at said first oflice for manually applying ringingcurrent to said trunk circuit from one of said sources, means at saidfirst oflice for automatically applying ringing current to said trunkcircuit from one of'said sources, means at said second ofiice fortesting the nature of the incoming ringing current, and means responsiveonly to the operation of said automatic applying means to open saidtalking connection at said second ofiic'e and to associate said testingmeans with said trunk.

7. In a telephone system, a first plurality of sources of ringingcurrent, a corresponding second plurality of sources of ringing current,a trunk circuit, means for manually applying ringing current from one ofsaid first plurality of sources to the incoming end of said trunkcircuit, means for automatically applying ringing current from one ofsaid first plurality of sources to the incoming end of said trunkcircuit, testing means for determining the nature of the ringing currentapplied, means responsive only to the operation of said automaticapplying means to associate said testing means with said trunk circuit,and means responsive to said testing means to ap ply ringing currentfrom the corresponding second source to the outgoing end of said trunkcircuit.

8. In a telephone system, a first office, a plurality of sources ofringing current at said first ofice, a second olfice, a correspondingsecond plurality of sources of ringing current at said second ofiice, atrunk circuit connecting said offices, a. subscribers substationincluding a switchhook contact, means for connecting said trunk circuitwith said substation, means for preparing a talking circuit over saidtrunk circuit to said substation, means at said first otfice forapplying ringing current from one of said sources to the incoming end ofsaid trunk circuit, testing means for determining the nature of theringing current applied, means responsive to the operation of saidapplying means to associate said testing means with said trunk circuit,means responsive to said testing means to connect ringing current fromthe corresponding second source to the outgoing end of said trunkcircuit and said substation, and means associated with said testingmeans responsive to the closure of said switchhook contact to cause thedisconnection of said applying means from said trunk circuit.

9. In a telephone system, a first ofiice, a plurality of sources ofringing current at sa d first oflice, a second ofii'ce, a correspondingsecond plurality of sources of ringing current at said second otfice, atrunk circuit connecting said oflices, a subscribers substationincluding a switchhook contact, means for connecting said trunk circuitwith said substation, means to prepare a talking circuit over said trunkcircuit to said substation, means at said firstofiice for applyingringing current from one of said sources to the incoming end of saidtrunk circuit, testing means for determining the nature of the ringingcurrent applied, means responsive to the operation of said applyingmeans for associating said testing means with said trunk circuit, meansresponsive to said testing means to connect ringing current from thecorresponding second source to the outgoing end of said trunk circuitand said substation,

and means associated with said testing means responsive to the closureof said switchhook contact to cause the removal of ringing currentfrom'both ends of said trunk circuit.

10. In a telephone system, a first quality of sources of ringingcurrent, a corresponding second plurality of sources of ringing current,a trunk circuit, means for manually applying ringing current from one ofsaid first plurality of sources to the incoming end of said trunkcircuit, means for automatically applying ringing current from one ofsaid first plurality of sources to the incoming end of said trunkcircuit, testing means for determining the nature of the ringing currentapplied, means responsive only to the operation of said automaticapplying means to associate said testing means with said trunk circuit,means responsive to said testing means to connect ringing current fromthe corresponding second source to the outgoing end of said trunkcircuit, and to said substation, and means associated with said testingmeans responsive to the closure of said switchhook contact to cause thedisconnection of said applying means from said trunk circuit.

11. In a telephone system, a first plurality of sources of ringingcurrent, a corresponding second plurality of sources of ringing current,a trunk circuit, means for manually applying ringing current from one ofsaid first plurality of sources to the incoming end of said trunkcircuit, means for automatically applying ringing current from one ofsaid 100 first plurality of sources to the incoming end of said trunkcircuit, testing means for determining the nature of the ringing currentapplied, means responsive only to the operation ofsaid automaticapplying means to as 105 sociate said testing means with said trunkcircuit, means responsive to said testing means to connect ringingcurrent from the corresponding second source to the outgoing end of saidtrunk circuit and said substation, and 0 means associated with saidtesting means responsive to the closure of said switchhook contact tocause the removal of ringing current from both ends of said trunkcircuit.

In witness whereof I hereunto subscribe 115 my name this 1st day ofSeptember, 1931.

JOHL W. GOODERHAM.

